Genetic studies on wool production traits in Rambouillet crossbred sheep in J & K State, India

Data on 4186 lambs pertaining to 94 rams of Rambouillet and their crosses over the ten years (1998-2007) at Government Sheep Breeding and Research Farm, Reasi, Jammu, were studied. The averages were 1.49 +/- 0.009 kg, 5.52 +/- 0.02 cm and 21.25 +/- 0.01 mu for greasy fleece weight (GFW), staple length (SL) and fiber diameter (141)) respectively. The highest CV (%) was observed for greasy fleece weight where as the lowest CV (%) was observed for fiber diameter. The least-squares means were 1.51 +/- 0.02 kg, 5.64 +/- 0.04 cm and 21.27 +/-.03 g for greasy fleece weight, staple length, and fiber diameter respectively. The effect of year of lambing had significant effect (P<0.01) for all the traits under present study. The effect of season of lambing was non-significant for all the traits. The effect of sex was significant (P<0.01) for greasy fleece weight only. However, no systematic trend was observed over the year, season of lambing and sex for all three the traits studied. The estimates of heritability were high for GFW (0.49) and FD (0.55), where as for SL it was low (0.15). The genetic and phenotypic correlations were either negative or low and in some cases it was both low and negative. These estimates revealed that there is scope for genetic improvement of these traits through appropriate selection methods and index.